Derivatives of fatty acids and method of preparing same



Patented Dec. 13, 1945" I e DERIVATIVES OF FATTY ACIDS AND METHOD OF PREPARING SAME John R. Long, Akron, Ohio, assignor to Wingfoot Corporation, Akron, Ohio, a corporation of Delaware I v No Drawing. Application August 8, 1941,

Serial No. 405,998

. 2Claims. (cl. 260--464) Thi invention relates to certain organic com- C.) or other suitable temperatures, usuall b pounds containingnitrogen and to a method of tween 500-600" C. The vapors leaving the furpreparlng the same. More particularly, it renace are cooled and then distilled in the preslat'es to'the preparation of eyanhydrin acetates ence or absence of a polymerization inhibitor,

of acetyl fatty acid esters and to substituted 5 such as hydroquinone. The product may be acrylonitriles which may be derived therefrom. termed an ester of a cyano acid or a'carboalkoxy .Various ketones have heretofore been treated nitrile and is obtained as a polymer or as monwith hydrogen cyanide to form cyanhydrins and omer. Of course, the procedure outlined for the these, in turn, may be acetylated to obtain the pyrolysis maybe employed with modifications in cyanhydrin acetates. It has now been found the pyrolysis of other cyanhydrln acetates.

that the keto acid esters may be similarly treated The reactions involved in the preparation proto yield valuable new compounds, the cyanhydrin ceed as follows:

acetates so produced being subjected to pyrolysis 0N The invention embraces cyanhydrins and cyl5 anhydrin acetates of acetyl fatty acid esters, and carboalkoxy alkyl substituted acrylonitriles de- QN rived from the cyanhydrln acetates. These comg CHDFC 0 012+ (A020 pounds may be obtained in a series of steps starting with a keto acid ester of the general formula H CH3-CO(CH2):COOR, where :c is zero or an UN,

integer and R is an ester-forming group, those r esters being preferred in which the acid con- CH?! (loom-Ho tains not more than four methylene groups.

Also, while R may be any ester-forming group, CN-

the alkyl esters are preferred, particularly the EA heat methyl esters. I

In the preparatio H:)=---COOR+HOA0 he compounds, the keto Ac acid ester, such as me yruvate, is treated and with hydrogen cyanide, usually in the presence 0N of sodium cyanide or a, similar catalyst. When CHS J}=CH (CHZ); I COOR the HCN gas has been absorbed in an amount corresponding to the molecular equivalent of the To illustrate n means of p epari t e comester, or more, or less, as may be desired, the pounds constltutmg 18 1 tter f t e mixture is permitted to stand. Preferably the invention; t e fo o e p es re elve temperature h d b t in t neighborhood though it will be understood that no limitation of -50" c. during the addition of th'e hydrogen s d d t reby.

cyanide. The cyanhydrin so formed may be sep- EXAMPLE 1 "arated or the mixture may be subjected to the r next step without such separation. In the next 40 cyanhydnn acetate of methyl pyatmwte operation, an acetylating agent, such as acetic Hydrogen cyanide gas was bubbled into 220 anhydride in the presence of sulfuric acid, is emgrams of methyl pyruvate containing several ployed, the cyanhydrin being added to the -acet-- grams of'NaCN until the weight had increased ylating agent while maintaining the tempera- 60 grams. This is slightly more than the theture at about 100-110" C., although the temperoretical amount corresponding to the methyl pyature may be varied as indicated by the course ruvate present. The temperature was mainof the reaction. The cyanhydrin acetate is tained at 40-50 C. during the additi n 01 t formed in this step and this product may be re- HCN. After standing overnight, the mixture covered by filtering'ofl solids and distilling to was poured into 224 grams of acetic anhydride remove acetic acid. Further purification may containing 10 grams of sulfuric acid, a temperbe required, as by distillation under a higher vacature of IOU-110 C. being maintained. The reuum. J action mixture was filtered to remove solids and The cyanhydrin acetate obtained by the forewas then distilled on a water pump to remove going procedure may then be pyrolyzed by heatacetic acid. The crude product was again dising in a furnace at a temperature of 535-550 tilled with the aid of an oil pump. The roduct obtained was the cyanhydrin acetate of methyl pyruvate having the formula The compound distills at ll'7-118 C. at 18 mm.; index of refraction n =1.4205; density (130 =1.131 5. N theory=8.20; Found=8.3'7.

EXAMPLE 2 Methyl alpha cyanoacrylate The cyanhydrin acetate obtained in the preceding example was subjected to pyrolysis in a pyrolysis chamber consisting of a 22 mm. Pyrex tube packed with copper turning and heated in a two-foot vertical furnace to a temperature of 535-550 C. After passage of the cyanh'ydrin acetate through the tube, the vapors given off were cooled by passing them through a watercooled condenser. One hundred and twenty-five grams of the cyanhydrin acetate of methyl pyruvate were passed through the furnace in 75 minutes under a pressure of 200 mm. The product was distilled under reduced pressure in the presence of h'ydroquinoneto drive off the acetic acid which results from pyrolysis. The product was methyl alpha cyanoacrylate:

and is obtained in polymeric form as a hard glasslike solid on cooling.

was passed hydrogen cyanide gas, in the presence of 3.0 grams of NaCN until the weight had increased 114 grams. The reaction mixture was kept at a temperatur of ill-50 C. during the addition of the HCN. The reaction mixture was allowed to stand overnight and was then added slowly, with shaking, to a mixture of 483 grams of acetic anhydride and 5.5 grams of H2804 kept at a temperature of IOU-120 C. This temperature was maintained for a half hour after the addition was completed. The acetic acid generated was distilled ofi with the aid of a water pump and the product residue distilled on an oil pump. The substance distilling between 115-130 C. under a pressure oi 2 mm. was taken to be the cyanhydrin acetate of methyl levulinate having the formula min. (i. d.) Pyrex tube filled with clay saddles. The tube was heated to a temperature of 565-585 C. in a 2% foot vertical wire-wound electric furnace. The vapors, on leaving the furnace, were cooled by passing them through a water con- (omega carboalkoxy alkyl) acrylonitriles.

denser. In the course of 2 /2 hours 468 grams of the cyanhydrin acetate was passed through the pyrolysis tube at a pressure of 30 35 mm. The crude product was fractionated under reduced pressureto obtain a main fraction distilling at SO- C. The product was probably alpha (beta carbomethoxy ethyl) acrylonitrile having the formula Its physical characteristics were as follows: 'Il =1,4478;d27=1.0352. N: Found 9.8, 9.9; Calc. 10.07. An isomeric substance may also be present having the formula:

carbomethoxy ethyl) acrylonitrile was emulsified in 20 cc. of an aqueous solution containing 0.266 gram of sodium perborate, the aqueous solution being made up of v 10 cc. of McIlvains buffer giving a hydrogen ion concentration of pH=4.1 and 10 cc. of 6 %'Dupono1 as an emulsifier. Th emulsion was agitated for a period of 42 hours at a temperature of 30 C. Thereafter, the polymer was coagulated with alcohol, washed and dried, a yield of 9.25 grams of a soft copolymer being obtained.

Other compounds similar to those herein described may also be prepared by the method disclosed or by similar methods. For example, the

methyl ester of acetobutyric acid and other omega acetyl fatty acid esters may be treated with hydrogen cyanid and acetic anhydride and may be subsequently pyrolyzed, all in a manner similar to that described above, to yield, particularly, the cyanhydrins and cyanhydrin acetates of omega acetyl fatty acid esters and the alpha Also, whilethe methyl esters have been mentioned, it will be obvious that ethyl, propyl, butyl, benzyl and higher esters may be prepared, although the methyl ester is preferred. The method of obtaining the materials may likewis be varied in many respects without'departing from the'scope of the invention.

Hence, while there have been described above the preferred embodiments of the invention, it will be apparent to those skilled in the art that various modifications and changes may be made therein without departing from the spirit of the 2. Theicyanhydrin acetate of methyl pyruvate.

JOHN R. LONG.

A mixture of 9.6 

